Selective control for an ice maker



Aug. 5, 1969 r s. SORENSEN SELECTIVE CONTROL FOR AN ICE MMjER 2 Sheets-Sheet 1 Filed Nov. 22. lgev INVBNTOP SVE/VQE SOQE/VSEN ATTOR N EY Aug. 5, 1969 s; EQSORENSEN SELECTIVE CONTROL FOR AN ICE MAKER 2 Sheets-Sheet 2 Filed Nov. 22, 1967 /l/l/ll/l/I INVENTOR SVE/VO E SOPE/VSE/V ATTOR N EY United States Patent Ofice 3,459,005 SELECTIVE CONTROL FOR AN ICE MAKER Svend E. Sorensen, York, Pa., assignor to Borg-Warner Corporation, Chicago, 11]., a corporation of Illinois Filed Nov. 22, 1967, Ser. No. 685,005 Int. Cl. F25c 1/06 US. Cl. 62-138 13 Claims ABSTRACT OF THE DISCLOSURE An apparatus for making chips or blocks of ice having a selectively variable control for regulating the size of ice chips, wherein during the freezing cycle of the apparatus ice is made in the control tube and the rate of ice formation is varied by a heater which supplies heat thereto. When the ice formed in the control tube blocks the tube, water backs up therein and causes an increase in pressure which triggers a harvest cycle during which the ice blocks are released into a suitable container. When the harvest cycle is completed, a temperature sensitive device switches the apparatus back into the ice freezing cycle.

Background and summary of the invention This invention relates to an apparatus for making chips or blocks of ice and more particularly to an apparatus for making chips of ice having a relatively simple, reliable and efficient means for selectively regulating the size of the ice chips made.

Ice makers have been constructed previously which made chips of ice and which automatically released the chips when they obtained a certain size, but these ice makers have been limited because no accurate means has been available for conventiently regulating the size of the ice made. The present invention is designed to overcome these limitations and to provide a relatively inexpensive and reliable control system for an ice making apparatus such that capacity is increased and the size of the chips may be easily, simply and reliably controlled.

A feature of this invention includes the provisionof means for selectively regulating the length of time of a freezing cycle of the apparatus.

Another feature of this invention includes the provision of a control ice freezing surface wherein the rate of freezing is selectively adjustable to control the size of the ice chips made by said apparatus.

A still further feature of the invention includes the provision of a heater means for selectively regulating the rate of freezing on said control ice freezing surface.

A still further feature of the invention includes the provision of means for automatically switching said apparatus from the freezing cycle to the harvest cycle and back again.

A specific feature of the invention relates to the construction of a control tube and control means for switching said apparatus from the freezing cycle to the harvest cycle.

This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction With the accompanying drawings which illustrate preferred embodiments.

Description of the drawings FIGURE 1 is a diagrammatic view of an ice maker constructed according to the principles of this invention;

FIGURE 2 is a cross sectional view of a portion of the ice chip maker of FIGURE 1, taken along the line 11-11 thereof;

FIGURE 3 is a cross section view of the control tube shown in diagrammatic form in FIGURE 1;

3,459,005 Patented Aug. 5, 1969 FIGURE 4 is an enlarged cross sectional view of a portion of the control tube of FIGURE 3;

FIGURE 5 is a cross sectional view of a portion of the control tube of FIGURE 3, taken along the line VV thereof; and

FIGURE 6 is a diagrammatic view of the electrical circuit for the ice maker of FIGURE 1.

The ice maker constructed according to the principles of this invention, designated generally at 10, has three main component portions--a refrigerating circuit; a water circuit; and a control circuit.

The refrigerating circuit (see FIGURE 1) comprises a compressor 11 driven by an electric motor 12, both of which are normally sealed within the same air tight casing to form a hermetic assembly. A hot refrigerant gas line 13 leads from the discharge of the compressor to a condenser 14, which may be cooled by water but is shown as being cooled by air from a fan 16 driven by electric drive motor 17. Refrigerant line 18 leads from the condenser to a liquid refrigerant receiver 19, which connects with refrigerant metering valve 21 by way of a liquid line 22. Expansion valve 21 may be of any suitable type, but comprises preferably a thermal expansion valve controlled by a bulb 23 connected thereto by way of a capillary 24, as is well known in the art. A loW pressure liquid line 26 leads from valve 21 to a secondary evaporator 27, which is in direct contact with the outer surface of a control ice-forming tube 28.

A complete description of the ice forming unit may be found in U.S. Patent 2,983,109, issued to M. G. Leeson on May 9, 1961; so the description which follows has been limited to that which is necessary to understand the operation of the present invention.

From the secondary evaporator 27 a refrigerant line 29 leads to a main or primary evaporator 31. Evaporator 31 is formed of a plurality of parallel rows of tubing bonded to a plurality of vertical ice-forming elements 33. The outlet of evaporator 31 is connected to the inlet of compressor 11 through a cold gas suction line 34 having a U-shaped drop leg 35 formed therein. The hot gas bypass connection 37 is controlled by a solenoid operated hot gas defrost valve 38 connecting lines 13 and 26.

The ice-forming elements 33 (see FIGURE 2) each comprise a vertically extending channel member having an ice-forming surface 40 and in-turned end portions 41 defining hexagonal-like passageways 42 with ice chips being formed opposite one another on opposed surfaces 40 for a maximum of ice chips in a minimum amount of space. It will be appreciated that in such a construction, the evaporator 31 will have parallel rows of tubing thereof suitably bonded on both sides of passageways 42 to form a freezing assembly 43.

The water circuit of the ice maker 10 serves to circulate water within the assembly 43 and over the surfaces 40 and 41 so that it may be frozen thereto to produce ice. A sump 48 beneath assembly 43 is provided for maintaining a reservoir of water available for this purpose. Pump 49, driven by an electric motor 51, has its inlet within the body of water and has its discharge connected to a line 52 leading to a water header 53, and a plurality of spray nozzles 54 attached thereto, one for each passageway 42. Water header 53 also has an outlet line 56 leading to control tube 28. Valve 57 controls the flow of make-up water into the sump 48 through a line 58 connected to any suitable source of water and is automatically operated by a float 59 which maintains an approximately constant level of water within the sump 48.

The control circuit is provided for rendering the entire operation of the ice maker 10 automatic, including means for initiating the freezing operation of the system wherein the circulated water is frozen into ice chips, means for automatically terminating the freezing operation and initiating a harvesting operation wherein the bond between the ice chips and the ice forming element 33 is broken and the ice chips fall into the bin 44, and means for automatically terminating operation of the machine when the ice in bin 44 reaches a certain predetermined level.

Referring now in particular to FIGURES 35, an important element in the automatic control circuit of the ice maker is the control tube 28, which comprises an upper tube portion 60 and lower tubular portion 61 which is surrounded by the coiled refrigerant evaporator 27 to freeze water flowing therethrough. The upper portion 60 may be of a generally cylindrical structure having an inner surface 62. A cylinder 63 is disposed within the tubular portion 60 and extends down into lower portion 61. A water pipe 64 and an electric resistance heater 65 extend into cylinder 63 through a stopper 66 which is fitted tightly into the top of the upper tube portion 60 in airtight relation against the inner surface 62 and around the inner cylinder 63, the heater tube 65a and water pipe 64. Stopper 66 also provides support for the control tube 28. The ice freezing tube portion 61 is fitted securely into the lower end of the upper portion 60. Radially extending spacer members 67 and 68 are fitted around the inner cylinder 63 and are effective to center and vertically position the inner cylinder 63 with respect to the tubular portions 60 and 61. Two air cavities 70 and 71 are formed in the control tube 28 by the stopper 66 and spacers 67 and 68. Openings 72 and 73 extend through spacers 67 and 68 while a passage 74 in stopper 66 connects the cavity 70 with a larger air tube 76, so that a continuous air passageway exits from the ice freezing portion 61 through the upper portion 60 and into the air tube 76. A nozzle 77 having orifices 78a and 78b is affixed on the lower end of the inner cylinder 63 and is designed to spray water onto the ice freezing surface 61a of the tube portion 61.

The water pipe 64 is connected to the outlet line 56 (FIGURE 1) from the water header 53, and extends only part of the way down into the inner cylinder 63. The heater 65 is connected to a heater lead 79 having two electric wires 81 and 82 therein for supplying current to the heater 65.

The power supply for the unit includes three terminals 84, 86 and 87. Two-hundred thirty (230) volts AC. is applied between terminals 86 and 87 while one-hundred fifteen (115) volts AC. is applied between terminals 84 and 86; so that terminal 86 and power line 85 connected thereto acts as a common ground for power lines 83 and 88 connected respectively to terminals 84 and 87.

Between conductors 85 and 88 are connected, in series, a solenoid 89, a high pressure cut out switch 91, a bin switch 130, and the main on/off switch 92 having a fixed contact 93 and off and on contacts 94, 95. In parallel with the above series connected elements are a normally open switch 96, controlled by solenoid 89 and connected to one terminal of the compressor motor 12, and a normally open switch 98, also controlled by solenoid 89 and connected between power line 85 and the other terminal of compressor motor 12. Conventional run and start capacitors, 12a and 12b respectively, are connected into the compressor motor circuit, as is understood by those skilled in the art.

Conductor 97 connects line 85 to one side of a pressuretemperature switch 100, which is connected to and controlled by air pressure in the air pipe 76 and a capillary tube 101 connected to a temperature sensing means 102 positioned on a portion of the ice freezing assembly 43. The pressure-temperature switch is preferably combined as a single unit, such as for example, a Robertshaw DS-12 control. The pressure-temperature switch 100 has two alternate contacts 103 and 104. Closing of contact 103 serves to energize the coil 38a of hot gas solenoid valve 38, the coil 106a of water drain solenoid valve 106, and the coil 132 of a bin switch lock-in relay switch 134.

The latter is operable to close normally open relay switch 134 connected across bin switch 130. Alternate contact 104 is connected to the on contact 107 of switch 108 having one terminal 109 connected to the pump motor 51. The pump motor switch 108 is controlled simultaneously with, and by the same means as, the main on/off switch 92, and these switches serve to activate and deactivate the whole ice maker 10. The terminal 104 of switch is also connected to a fixed contact 111 of a four place heater control switch 112 having a first fixed contact 113 connected to the heater line 81, a second fixed contact 114 connected through a resistor 116 to the line 81, a third fixed contact 117 connected through a resistor 118 to the line 81, and a fourth fixed contact 121 which is an open contact.

The bin switch may be mechanically controlled by a mechanism (not shown) which opens switch 130 when the bin 44 is filled to a certain level. The bin switch 130 may also be actuated by a thermostat as in US. Patent 2,983,109. As long as the ice maker 10 is turned on, with on/ off switches 92 and 108 in the on position, the ice maker 10 is operational. If switch 130 is closed, thus indicating a demand for ice, then the ice maker 10 is either in the freezing cycle or the harvesting cycle. Let us assume the ice maker 10 is in the freezing cycle. Pressure-temperature switch 100 is operative to connect the line 97 with the terminal 104, to activate the water pump motor 51 through switch 108. The heater 65 is also energized through the switch 112, which is shown set on the first contact 113. The hot gas defrost solenoid 38a, the drain solenoid 106a and the bin switch lock-in relay solenoid 132 are de-energized. It should be noted that the circuit schematic is for a system using a water cooled condenser. In the event an air-cooled system is used, condenser fan motor 17 (FIGURE 1) would be energized at this time.

The compressor 11, condenser 14, refrigerant metering valve 21 and the evaporators function in a manner well known in the art to cool the refrigerant evaporators 27 and 31 well below the freezing point; and the evaporators 27 and 31 serve to cool the ice freezing portion 61 of control tube 28 and the ice freezing elements 33 of the apparatus 43 respectively, as has been described earlier. Meanwhile, the pump 49 supplies water to the water header 53 from which it is delivered to the ice freezing surfaces in a manner which has also been described, and ice forms on these surfaces.

During this freezing cycle of the ice maker 10, the control tube 28 functions in a simple, reliable and efiicient manner to regulate the length of time of the freezing cycle and thus the size of the ice chips formed in the ice freezing apparatus 43. Water is supplied at a relatively constant flow rate via line 56 and pipe 64 into the inner cylinder 63, from which it is sprayed by the nozzle 77, through orifices 78a and 78b, onto the surface of tube portion 61 and frozen thereon. The rate of freezing of the water in tube portion 61 depends upon the temperature of the tube portion and the temperature of the water sprayed thereon. While the water in line 56 is supplied at an inlet temperature of approximately 32 F., the temperature of the water in nozzle 77 is affected by the heater 65, which supplies heat primarily to the water as it travels through pipe 64 and sits in the lower portion of cylinder 63. The amount of heat supplied by the heater 65 thus determines the rate of freezing of the water in the tube portion 61. A 30-watt resistance type heater disposed in the lower part of the tube 65a has been found satisfactory for this purpose. Heater means could be disposed in other positions along the tube 65. As water freezes in tube portion 61, ice builds up therein; and at a certain point, the ice substantially closes the path through the tube portion 61. Water from the cylinder 63 then begins to back up or rise in the upper part of the portion 61, and may even rise up through the openings 73 and 72 into the air passages 70 and air pressure builds up in the passage 70. Since the air passages 71 and 70 are connected with portion 61, the increased air pressure is transmitted through these passages and into the air pipe 76, where it is transmitted to the pressure-temperature controlled switch 100. Switch 100 is of a type which is known in the art, and it is operative to react to the increased pressure from pipe 76 to switch the electrical contact of line 97 from the terminal 104 to the terminal 103. The pump 49 and condenser fan motor 17 are thus de-energized and the ice maker is switched into its harvesting cycle.

In the harvesting cycle, the solenoid 38a is energized to open valve 38, and the solenoid 196a is energized to open its associated drain valve 106. Solenoid 132 also is energized to close normally open lock-in relay switch 134. Hot gas from the compressor 11 is transmitted through open valve 38 through lines 37, 26 and 29 and into the evaporator sections 27 and 31. The ice chips in the apparatus 43 are thus harvested; and the ice in control tube 28 is melted to drop out the bottom of portion 61, because of the heat from the hot gas passing through evaporator 27. The lock-in relay switch 134 assures completion of the harvest cycle. :If, for example, bin switch 130 were to open during the harvest cycle, the operation of the whole unit might cease without some means to prevent this occurrence. To assure continuation of the reharvesting, the energized solenoid 132 closes relay switch 134 by-passing switch 130 to keep the circuit closed and the ice maker operating.

When the temperature in the ice freezing apparatus 43 rises above a certain level, the temperature sensing bulb 102 causes the pressure-temperature switch 100 to switch the line 97 from the terminal 103 back to the terminal 104 and the ice maker 10 returns to the freezing cycle. This cycling process continues as long as the ice maker 10 is turned on and the ice in the bin 44 is not high enough to cause switch 130 to open.

The method of regulating the size of the ice chips made by the freezing assembly 43 should now be explained. This regulation is accomplished by regulating the amount of heat output of the heater 65 during the freezing cycle, which controls the rate of freezing in the control tube 28 and thus the length of time required before ice builds up therein and causes the ice maker 10 to switch into the harvesting cycle. As shown in FIGURES 1 and 6, the heater 65 is supplied with power from terminal 104 through the switch 112, which is shown contacting the first fixed contact 113. The switch 112 controls the amount of current supplied to heater 65 and thus the size of the ice chips made. Switch 112 is shown in the first position, wherein the largest amount of current is supplied to heater 65 thus supplying the greatest amount of heat to retard freezing for the longest period of time causing the longest freezing cycle and therefore the largest ice chips, king-sized ice chips. If switch 112 is turned to contact 114, resistor 11 6 is of a value to cause a decrease in the amount of current to heater 65 and a corresponding decrease in the freezing cycle time. [If switch 112 is turned to contact 117, the resistor 118 which has a greater resistance than resistor 116 causes a still further decrease in the current to heater 65 and a still further decrease in the size of ice chips. If switch 112 is turned to contact 121, no heat is produced by heater 65 and the shortest freezing cycle is attained, thereby causing small chips to be made. In this manner, the size of ice chips made by the ice maker 10 is easily, conventiently and reliably controlled in a simple and eflicient manner.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim:

1. In an apparatus for making blocks of ice the combination comprising: a first ice freezing surface, a second control ice freezing surface, means for flowing water to be frozen over said first and second ice freezing surfaces, refrigerant evaporator means associated with each of said freezing surfaces to form ice thereon, and control means for selectively regulating the amount of time during which ice is formed on said first ice freezing surface and thereby regulating the size of ice blocks to be produced by the apparatus, said control means including means for selectively regulating the rate of ice formation on said second control ice freezing surface, said means including heater means and means for selectively varying the output thereof to thereby vary the rate of freezing water on said second control ice freezing surface.

2. The combination of claim 1 wherein said heater means comprises an electric resistance heating element. 3. The combination of claim 2 wherein said means for selectively varing the output of said heater means includes a plurality of resistance members and switch means for selectively operatively connecting one of said resistance members to said heater means. 4. The combination of claim 1 including variable resistance means operatively associated with said heater means for varying the heat output thereof whereby the rate of freezing of water on said control surface may be varied to thereby regulate the length of the freezing cycle and thereby the size of ice blocks to be made by said icemaking apparatus. 5. In an apparatus for making blocks of ice the combination comprising:

a first ice freezing surface, a second control ice freezing surface, means for flowing water to be frozen over said first and second surfaces, refrigerant evaporator means associated with each of said freezing surfaces to form ice thereon, control means for regulating the size of the blocks of ice to be formed on said first freezing surface, including heater means for controlling the rate of freezing water on said second control ice freezing surface, and means responsive to the amount of ice formed on said control ice freezing surface to cause said control means to discontinue the freezing operation of said apparatus. 6. The combination of claim 5 wherein said control means comprises a control tube means, said second control in freezing surface comprises a portion of said control tube means and said heater means is operatively associated with said control tube means.

7. The combination of claim 6 wherein 8. The combination of claim 6 wherein said control tube means includes first and second tube members, said second tube member being disposed within said first tube member, and

said means for flowing water over said second control ice freezing surface includes conduit means extending into said second tube member for discharging water thereinto.

9. The combination of claim 8 wherein said heater means is disposed within said second tube member and adapted to heat water discharged into said second tube member.

10. The combination of claim 5 wherein said means responsive to the amount of ice formed on said control ice freezing surface to cause said control means to discontinue the freezing operation of said apparatus includes a pressure sensitive first sensing means responsive to a build-up of air pressure in said control means for terminating the freezing operation and starting the harvesting operation.

7 11. The combination of claim 10 further including a temperature sensitive second sensing means for terminating the harvesting cycle and reinitiating the freezing cycle. 12. The combination of claim 11 further including means operatively associated with and responsive to said first and second sensing means for controlling the flow or refrigerant through said evaporator means. 13. The combination of claim 5 wherein said control means includes a generally tubular element,

said second control surface comprising a portion of the inside surface of said tubular element, and said means responsive to the amount of ice formed on said second control ice freezing surface includes pressure sensitive fire sensing means, and means for connecting one end of said tubular element to said first sensing means in a substantially airtight relationship so that when the outlet from said tubular element is substantially blocked by the formation of ice on said control surface thus preventing the flow of water 5 therethrough, the pressure in said tubular element rises and is transmitted to said pressure sensitive first sensing means.

10 References Cited UNITED STATES PATENTS 2,983,109 5/1961 Leeson 6271 3,220,207 11/1965 Cordes 62138 15 WILLIAM E. WAYNE, Primary Examiner US. Cl. X.R. 62233 Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,459,005 August 5, 1969 Svend E. Sorensen It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6 line 48 "in" should read ice Column 7, line 18, "fire" should read first Signed and sealed this 30th day of June 1970.

(SEAL) Attest:

Edward M. Fletcher, J r.

Commissioner of Patents WILLIAM E. SCHUYLER, JR. 

